Move PolicyMap and its dependencies to components/policy/.

chrome/browser/policy/external_data_fetcher.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_POLICY_EXTERNAL_DATA_FETCHER_H_
-#define CHROME_BROWSER_POLICY_EXTERNAL_DATA_FETCHER_H_
-
-#include <string>
-
-#include "base/callback_forward.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-
-namespace policy {
-
-class ExternalDataManager;
-
-// A helper that encapsulates the parameters required to retrieve the external
-// data for a policy.
-class ExternalDataFetcher {
- public:
-  typedef base::Callback<void(scoped_ptr<std::string>)> FetchCallback;
-
-  // This instance's Fetch() method will instruct the |manager| to retrieve the
-  // external data referenced by the given |policy|.
-  ExternalDataFetcher(base::WeakPtr<ExternalDataManager> manager,
-                      const std::string& policy);
-  ExternalDataFetcher(const ExternalDataFetcher& other);
-
-  ~ExternalDataFetcher();
-
-  static bool Equals(const ExternalDataFetcher* first,
-                     const ExternalDataFetcher* second);
-
-  // Retrieves the external data referenced by |policy_| and invokes |callback|
-  // with the result. If |policy_| does not reference any external data, the
-  // |callback| is invoked with a NULL pointer. Otherwise, the |callback| is
-  // invoked with the referenced data once it has been successfully retrieved.
-  // If retrieval is temporarily impossible (e.g. no network connectivity), the
-  // |callback| will be invoked when the temporary hindrance is resolved. If
-  // retrieval is permanently impossible (e.g. |policy_| references data that
-  // does not exist on the server), the |callback| will never be invoked.
-  void Fetch(const FetchCallback& callback) const;
-
- private:
-  base::WeakPtr<ExternalDataManager> manager_;
-  const std::string policy_;
-};
-
-}  // namespace policy
-
-#endif  // CHROME_BROWSER_POLICY_EXTERNAL_DATA_FETCHER_H_